• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1962-1967
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• 2008

A event recorder system stores a train speed and the related information for train operation in real time. Using those information, we can analysis the train operation and the reason of train accident. Currently the event recorder only manipulate the data related the train operation mechanically and electrically. In this paper we propose the event recorder to record the voice communication between the manager in the control center and train operator. By recording the voice communication in the high speed train, the correctness of analysis of train accident can be increased. The system architecture of the event recorder with voice recording is studied and interface between other equipment is proposed. And the software architecture of new event recorder is developed. We study the method of converting analog voice signal into digital data and compressing method. Also the architecture of memory to store the compressed voice data and regeneration of original analog voice are studied.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1005-1009
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• 2005

The On Board Computer System (ORCS) used for rolling stocks is one of the core equipments in trains, which deals with collecting real-time data of a train to display and record the train's statuses, control the train, and support the driver and maintenance function. Resides, due to high reliability and high speed communication required lately for various electronics including signal1ing devices, train protection system, and multimedia, the necessity of a more robust train communication network is on the lise. This study aims at understanding the technological trend of the current train communication network in order to rapidly cope with the tendency above and providing fundamental data for designing a more advanced communication network for high-speed trains hereafter.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.2
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• pp.118-125
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• 2022

With the aim to maximize the use of a given voltage source in the field of railway and electric vehicles, this study applies a technique for controlling the overmodulation region between the linear and the six-step regions. High linearity overmodulation techniques that do not use look-up table (LUT) to digital signal processor (DSP) using carrier based pulse width modulation (PWM) are proposed. Such technique requires the phase of the voltage vector at the point where the circular trajectory of the voltage command vector and hexagonal cross each other. Therefore, a method is proposed to obtain a phase of a voltage vector that is derived through an equation and applied to a carrier-based PWM. Validity of the proposed implementation method is confirmed through simulation and experiment.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1044-1053
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• 2010

Transmitting correct train control information is important in a train control system which demands safety. The train control information includes the maximum speed of trains, position of preceding trains, incline of tracks and curve sections etc. A radio frequency-communication based train control system is influenced by the noise and interference because the train control information is transmitted by wireless between a on-board system and wayside system. The radio frequency-communication based train control system is a mobile communication system due to moving trains. The inter symbol interference(ISI) occurs by the multipath fading in the mobile ommunication system. As signal-to-noise ratio(SNR) is decreased by the ISI, the train control information is not received correctly. In case of tunnel section, numerous reflected waves exist. Therefore, the power density of receiver is decreased by difference among the received times, magnitudes, phases through the multipath. So, the train suddenly is stopped by the fail-safe operation in the train control system on account of decreasing the power density of receiver. In this paper, a line of sight model-(Additive White Gaussian noise(AWGN) channel), rayleigh and rician fading model are presented. Probability density functions which are related to the SNR are derived from the models. The fading phenomenon severely occurs as a result of analyzing the probability density functions. So, the space diversity method is used in order to reduce the fading effect and it is demonstrated by using Matlab program.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.211-225
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• 2011

Railroad signalling systems are to control intervals and routes of trains. There are ATS(Automatic Train Stop), ATP(Automatic Train Protection), ATO(Automatic Train Operation) and ATC(Automatic Train Control) system. Trains are operated in the section which is met on the signalling system because various signalling systems are used in Korea. On the other words, trains are not operated in the section which is used in the other signalling system. To solve this problem, recently combined on-board system has been developed. The combined on-board system is designed by doubling the ATS, ATP and ATC system. Information signal is received by magnetic sensors in the ATC system and is received by antennas in the ATS and ATP system. Therefore, it is possible to arise transmission problems by magnetic coupling. In this paper, electric model of the ATS and ATP antenna is suggested and interference frequency by the magnetic coupling between the ATS and ATP antenna is estimated numerically. As a results of the magnetic coupling, the value of the magnetic coupling is presented without magnetic induction.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.236-246
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• 2003

This paper is implemented a control algorithm in order to be stable and minimized to entire train traffic system at delayed case. Signal ing system is described wi th algebraic equations given for train headway, Discrete-event simulation principles are reviewed and a demonstration block signaling model using the technique is implemented. Train congestion at station entrance for short headway operation is demonstrated and the propagation of delays along a platform of trains from any imposed delay to the leading train is also shown. A rail way signaling system is by nature a distributed operation with event triggered at discrete intervals. Although the train kinematic variables of position, velocity, and acceleration are continually changing, the changes are triggered when the trains pass over section boundaries and arrive at signals and route switches. This paper deals with linear-mode1ing, stability and optimal control for the traffic on such metro line of the model is reconstructed in order to adapt the circuits. This paper propose optimal control laws wi th state feedback ensuring the stability of the modeled system for circuits. Simulation results show the benefit to be expected from an efficient traffic control. The main results are summarized as follows: 1. In this paper we develop a linear model describing the traffic for both loop lines, two state space equations have been analyzed. The first one is adapted to the situation where a complete nominal time schedule is available while second one is adapted when only the nominal time interval between trains is known, in both cases we show the unstability of the traffic when the proceeding train is delayed following properties, - They are easily implemented at law cost on existing lines. - They ensure the exponetial stability of loop system. 2. These control laws have been tested on a traffic simulation software taking into the non-linearites and the physical constraints on a metro line. By means of simulation, the efficiency of the proposed optimal control laws are shown.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.34 no.6
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• pp.363-370
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• 2021

In this paper, we presented an optimized crack and flexural strength analysis of a glass-fiber reinforced polymer (GFRP) rebar, used as reinforcements for in-site railway concrete slabs. The insulation performance of a GFRP rebar has the advantage of avoiding the loss of signal current in an audio frequency (AF) track circuit. A full-scale experiment, and three-dimensional finite element simulation results were compared to validate our approaches. Parametric numerical results revealed that the diameters and arrangements of the GFRP rebar had a significant effect on the flexural strength and crack control performances of the concrete track slabs. The results of this study could serve as a benchmark for future guidelines in designing more efficient, and economical concrete slabs using the GFRP rebar.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.2
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• pp.256-263
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• 2009

KORAIL carries out an improvement project of railway signaling system for the conventional line from the existing method which permits a train to move within limited speed the ground signal of ATS(Automatic Train Stop) system. The proposed system makes possible that a train can be driven using a speed profile created by onboard signaling system(ATP) with the movement authority from ground balise. A driving test over 100,000km is being executed by developing a tilting train for the speed elevation on the conventional line. And, the introduction of the tilting train by ATP system to the Jung-ang line is expected. However, a speed elevation on a curved line section has a restriction. Therefore, research on safety braking model and train separation control technology for the localization of ATP system is required preferentially. In this paper, we presented a safety braking model of ATP system and a train separation control method that use ground balise as variable information provider, and executed a performance simulation.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1510-1512
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• 2004

Platform Screen Door System is a facility on platform to separate platform from track, having automatic sliding door structures interlocked to opening and closing of train door with integrated control unit. When a train comes to a stop at a designed position at a station, onboard ATC/ATO system transmits train berth signal to wayside signaling system. In case of automatic/driverless operation, opening and closing of the Platform Screen Door will be controlled by wayside signaling system. Unfortunately, we often see the case in news that passengers fall into track and their contact with train lead to critical accidents. However, passengers will be free from such accidents on the platform with the Platform Screen Door System. Especially during the rush hours, to ensure passenger's safety and smooth getting on & off, it is necessary to arrange. some station staffs on the platform without the Platform Screen Door System. On the other hand, the Platform Screen Door System will realize such operation by fewer staffs. Due to the above reasons, the Platform Screen Door System is becoming more popular in subway system recently.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1999-2004
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• 2009

Since 2003, the domestic ground signalling system of the Kyeongbu and Honam lines has been steadily improving with the introduction of the ATP system and application of the system to the train is actively being pursued for 2009 target. Therefore, new ground signalling systems are being installed to the trains and track conditions to control the train speed to a maximum of either 80km/h, 120km/h, 150km/h, or 160km/h. As well, considering safe breaking distance, block signalling has been installed and also the change over times of the track switching device has been adjusted according to the train speed. Since the new Tilting trains will be running faster than present trains, at speeds over 180 km/h, we anticipate that there will be problems with present signalling facilities. Therefore this paper attempts to examine the various problems with the interface between the ATP signalling system and the new Tilting trains and also it will propose the most effective operating plan based upon case studies of successful foreign operations.